I'm considering changing my 1950's (?) Bosch JU4 magneto on my T to a more period correct unit.
Here are my choices, the JU4 is in to the left in the back row, a 1930's Bosch FU4B to the right. In the front row three Model T period magnetos I think, a Eisemann Type G4 edit 2, an American Bosch U4 edit 2 and a Simms C4.
The JU4, the FU4B and the Simms are the ones with a good spark, so I'm considering using the Simms.
It's also the only left rotating of the bunch so it'll work with a sprocket I found for the camshaft (double as many teeth as the magneto sprocket since the camshaft goes half speed and opposite direction from the crank)
Here's another photo of the Simms C4:
There is excessive play in the sprocket end of the shaft, so I took it apart.
Everything looks nice - the bearing had just minor putting in the outer race. The outer race fell out without effort, maybe the housing is enlarged so shimming is needed? There is a fiber shim already for electrical isolation.
I've bought new E15 magneto bearings, but I wonder how I best can remove the old ones? No space to fit a regular puller and the bakelite ring close by looks very brittle.
Do I need a special puller or could grinding off the old bearing with a dremel be an alternative?
Would packing the new bearings with bearing grease be an alternative to the oiling originally used?
Anyone who knows how to test the capacitor? (I can't even find one..?)
Ok, it's best to leave it to a magneto specialist, but if its doable then I'm always willing to try cobble it together myself - might learn something new
My favorite is the Splitdorf. The quality of the design and materials is impressive. I'll try to post some pictures
Sure Splitdorf is among the best, it's just that I haven't found any for max $50 yet, as the others I've picked up over the years ;)
Here is a source of parts and information, including rebuilt magnetos. Although this is an old catalog, we have been using Marks recently for magnetos for our tractors. There must be an email available...have not researched.